The present disclosure relates to a display unit and a displaying method that display an image or the like, and recording medium holding a program that executes the displaying method. More specifically the present disclosure relates to technology applied to a display unit including a backlight.
When a display unit such as a liquid crystal display panel displays an image of a rapidly moving object, so-called motion blur in which the image looks blurred may occur. For example, when the liquid crystal display panel displays an image of an object moving at high speed from the left to the right on a screen, for a person watching the image, a contour of the moving object appears blurred. The motion blur occurs in an image displaying method called “hold-type displaying”.
In related art, as a technique of reducing motion blur in a display unit including a liquid crystal display panel, for example, it is known that a backlight illuminating a back surface of the liquid crystal display panel is turned on and off at high speed in conjunction with an image display period to shorten duration in which an image is displayed. In other words, motion blur that is an issue specific to the liquid crystal display panel is allowed to be reduced by adopting a displaying mode close to impulse-type displaying, as with a display unit using a CRT (Cathode Ray Tube) in related art.
FIGS. 12A and 12B illustrate an example of a configuration for performing on-off control of a backlight in related art. As illustrated in FIGS. 12A and 12B, the backlight is configured of a light guide plate 1 and light-emitting diodes 2a to 2f and 3a to 3f emitting light toward the light guide plate 1. FIG. 12A and FIG. 12B are a front view and a side view of the light guide plate 1, respectively.
As illustrated in FIG. 12A, the light guide plate 1 has six regions 1a, 1b, 1c, 1d, 1e, and 1f, and the light-emitting diodes 2a to 2f and the light-emitting diodes 3a to 3f are disposed on side surfaces of the regions 1a to 1f, respectively. For example, the light-emitting diodes 2a and 2b are disposed on one side surface and the other side surface of the region 1a, respectively. Such a backlight including light sources on side surfaces of the light guide plate is called an edge-light system.
Each of the regions 1a, 1b, 1c, 1d, 1e, and 1f is configured to emit light by light incident from the light-emitting diodes that are disposed on the side surfaces thereof, and not to propagate the light toward other regions. For example, the light-emitting diodes 2a and 3a emit light to allow the region 1a of the light guide plate 1 to emit light.
A liquid crystal display panel is disposed on a front surface of the backlight as illustrated in FIGS. 12A and 12B, and the six regions 1a to 1f of the light guide plate 1 are allowed to sequentially emit light for a short time. A process of allowing these six regions 1a to 1f to sequentially emit light is performed in one field period of an image displayed on the liquid crystal display panel, and light is sequentially emitted from the regions in order in which the image on the liquid crystal display panel is rewritten. When light emission of the backlight is controlled in such a manner, an image displayed on the liquid crystal display panel that is located on the front surface of the backlight is displayed on each of the regions for a short time. It is to be noted that a period in which the backlight is turned on and off is preferably too short for a person watching a displayed image to recognize blinking of the backlight.
When on-off control is performed on each of the regions of the backlight in such a manner, the display unit including the liquid crystal display panel is allowed to display an image with unnoticeable motion blur.
Incidentally, it has been proposed to use a polymer dispersed liquid crystal (PDLC) as the backlight disposed on the back surface of a liquid crystal display panel.
A light guide member for backlight in related art is formed by mixing a scattering material into a transparent resin material to form a mixture, and molding the mixture, and a surface of the backlight emits light with uniform luminance by a function of the scattering material. On the other hand, a surface of a backlight including the PDLC emits light by a scattering function of the PDLC. The PDLC is capable of controlling a light scattering state. In Japanese Unexamined Patent Application Publication No. 2012-141588, an example of a backlight using the PDLC is described.